High long-term test–retest reliability for extrastriatal 11C-raclopride binding in healthy older adults

Research output: Contribution to journalJournal articleResearchpeer-review

  • Nina Karalija
  • Lars Jonassson
  • Jarkko Johansson
  • Goran Papenberg
  • Alireza Salami
  • Micael Andersson
  • Katrine Riklund
  • Lars Nyberg
  • Boraxbekk, Carl-Johan Oskar

In vivo dopamine D2-receptor availability is frequently assessed with 11C-raclopride and positron emission tomography. Due to low signal-to-noise ratios for 11C-raclopride in areas with low D2 receptor densities, the ligand has been considered unreliable for measurements outside the dopamine-dense striatum. Intriguingly, recent studies show that extrastriatal 11C-raclopride binding potential (BPND) values are (i) reliably higher than in the cerebellum (where D2-receptor levels are negligible), (ii) correlate with behavior in the expected direction, and (iii) showed good test–retest reliability in a sample of younger adults. The present work demonstrates high seven-month test–retest reliability of striatal and extrastriatal 11C-raclopride BPND values in healthy, older adults (n = 27, age: 64–78 years). Mean 11C-raclopride BPND values were stable between test sessions in subcortical nuclei, and in frontal and temporal cortices (p > 0.05). Across all structures analyzed, intraclass correlation coefficients were high (0.85–0.96), absolute variability was low (mean: 4–8%), and coefficients of variance ranged between 9 and 25%. Furthermore, regional 11C-raclopride BPND values correlated with previously determined 18F-fallypride BPND values (ρ = 0.97 and 0.92 in correlations with and without striatal values, respectively, p < 0.01) and postmortem determined D2-receptor densities (including striatum: ρ = 0.92; p < 0.001; excluding striatum: ρ = 0.75; p = 0.067). These observations suggest that extrastriatal 11C-raclopride measurements represent a true D2 signal.

Original languageEnglish
JournalJournal of Cerebral Blood Flow and Metabolism
Volume40
Issue number9
Pages (from-to)1859-1868
Number of pages10
ISSN0271-678X
DOIs
Publication statusPublished - 2020

Bibliographical note

Publisher Copyright:
© The Author(s) 2019.

    Research areas

  • C-raclopride, binding potential, extrastriatal, positron emission tomography, reliability

ID: 332184895